The accuracy of intestinal ultrasound compared with small bowel capsule endoscopy in assessment of suspected Crohn’s disease in patients with negative ileocolonoscopy

BACKGROUND: Small bowel involvement in Crohn’s disease (CD) is frequently proximal to the ileocecal valve and inaccessible by conventional ileocolonoscopy (IC). Small bowel capsule endoscopy (SBCE) is among the prime modalities for assessment of small bowel disease in these patients. Intestinal ultrasound (IUS) is an accurate bedside fast and low-cost diagnostic modality utilized in CD for both diagnosis and monitoring. The aim of this study was to examine the accuracy of IUS in patients with suspected CD after a negative IC, and to evaluate the correlation of IUS with SBCE, inflammatory biomarkers and other cross-sectional imaging techniques. METHODS: Prospective single center study in which patients with suspected CD underwent IUS and SBCE examinations within 3 days. IUS results were blindly compared with SBCE that served as the gold standard. A post hoc comparison was performed of IUS and SBCE results and available cross-sectional imaging results (computed tomography or magnetic resonance enterography) as well as inflammatory biomarkers if measured. The study cohort was followed for 1 year. In case of discordance between the IUS and SBCE results, the diagnosis at 1 year was reported. RESULTS: Fifty patients were included in the study. The diagnostic yield of both IUS and SBCE for the diagnosis of small bowel CD was 38%. The IUS findings significantly correlated to small bowel inflammation detected by SBCE (r = 0.532, p < 0.001), with fair sensitivity and specificity (72% and 84%). Cross-sectional imaging results significantly correlated to IUS as well (r = 0.46, p = 0.018). Follow up was available in 8 of the 10 cases of discordance between IUS and SBCE. In all of these cases, diagnosis of CD was not fully established at the end of the follow up. CONCLUSIONS: The diagnostic yield of CE and IUS for detection of CD in patients with negative ileocolonoscopy was similar. IUS can be a useful diagnostic tool in suspected CD when IC is negative.